In recent years, a light-emitting device using, as a pixel, a light-emitting element which emits light by current excitation has been developed actively. Such light-emitting devices are incorporated in electronic devices such as a television image receiver, and are known as devices which provide images to users of the electronic devices.
In a light-emitting device, light-emitting elements for red, blue and green are provided. Light emitted from each of the light-emitting elements is combined while changing luminance, emission time and the like, thereby an image having different brightness, chromaticity, or gradation is displayed.
Most of light-emitting devices which have ever been developed have structures of a combination of red light, blue light and green light. However, for example, as described in Patent Document 1, a display device having a structure provided with a light-emitting element for emitting white emission has been developed.    Patent Document 1—Japanese Patent Laid-Open No. 2000-200061 bulletin
It is an object of the present invention to provide a light-emitting device and an electronic device which can provide an image with excellent image quality.